We have found that during the in vivo DES induced differentiation of immature hen oviducts there is a significant increase in the rate and extent of transfer of (C14)-mannose from GDP-man-(C14) to form mannosyl phosphoryl dolichol, mannosyl oligosaccharide phospholipid and mannosylated glycoproteins. We plan to study several other reactions involved in the lipid intermediate pathway of protein glycosylation during DES induced differentiation in order to determine which steps are subject to regulation. We will also try to detect phosphorylation of exogenously added dolichol. The pathway may be regulated by increasing the levels of endogenous acceptors rather than by increasing glycosyl transferase activity. We have also detected the presence of mannosyl phosphoryl dolichol in bone marrow and will determine whether the entire lipid intermediate pathway is present in bone marrow and whether this pathway has any role in erythroporiesis. BIBLIOGRAPHIC REFERENCES: Lucas, J.J. and Waechter, C.J. (1976). "Polyisoprenoid Glycolipids Involved in Glycoprotein Biosynthesis", Mol. Cell. Biochem. In Press. Lucas, J.J. (1976). "Increase in the Mannosyl Phosphoryl Dolichol Pathway of Glycoprotein Glycosylation in Differentiating Hen Oviduct". Fed. Proc. In Press.